delphi communication between applications

If you can get 1-3 working within the application then it will also work between two different instances of that application. If you don't want the user to be able to drag from and drop on the same label, then disable the drop target when you start the drag and enable it again when the drag is done. In the label OnMouseDown handler use DragDetectPlus to detect the start of a drag and then initiate the drag on the drop source. Register the label as a drop target and do what ever you need to do in the OnDrop handler. Put a drop target and a drop source component on the form. If you just want to react to the action of dragging one label to another (in two different instances of the same application), then you can either register a custom clipboard format (see the CustomFormat examples) and drag that or you can just 'misuse' the text format and drag some magic text string. You can't use that to drag between applications. The code you've shown is using VCL drag/drop. How to handle drag&drop between this label in each running application ? Style = OldCreateOrder = False OnCreate = FormCreate PixelsPerInch = 96 TextHeight = 13 object Label1 : TLabel Caption = 'Drag Label' DragMode = dmAutomaticīetween 2 components on the same form or application it's not a problem.īut execute 2 times this application : Drag&drop from label1 in application 1 to label1 in application 2 is not working. Unit17.dfm : object Form17 : TForm17 Left = 0 Top = 0 Caption = 'Form17' ClientHeight = 347 ClientWidth = 728 Color = clBtnFaceįont. Label1DragOver ( Sender, Source : TObject X, Y : Integer State : TDragState var Accept : Boolean ) beginĪccept := true Showmessage ( 'DragOVer from ' + Sender. Procedure Label1DragOver ( Sender, Source : TObject X, Y : Integer State : TDragState var Accept : Boolean ) private end var Form17 : TForm17 TForm17 = class ( TForm ) Label1 : TLabel Nddeapi.dll is present on Windows Vista, but all function calls return NDDENOTIMPLEMENTED. On at 7:20 AM, Jacek Laskowski said: from Microsft site: ' Network DDE is no longer supported. But not file or URL just 'common' Delphi components. Another alternative for IPC on a single computer is the WMCOPYDATA message, see Using Data Copy. I use Drag and Drop Component Suite since a long time and its work fine.īut I don't know how to handle drag&drop between 2 VCL applications (same application execute at same time for example).

Delphi communication between applications